Development And Growth

Each baby is an individual with a unique temperament and personality. Your newborn differs from others in his appearance; activity level; response to pain, hunger, or boredom; and sleeping and eating patterns. Your child is like a puzzle; it will take time for you to figure him out. If you remember that your child is an individual, not a reflection of you, it will make the job of parenting easier. Some babies are more difficult to live with than others. An infant who has a combination of intense reactions, irregularity, slow adaptability, and a high activity level is difficult to care for; you will need to be more patient and flexible parents. As you get to know your baby, you will learn about his temperament and learn to care for him in a more effective or satisfying way.   

Developmental Milestones

Here is a list of developmental characteristics and behaviors and the ages at which your baby is most likely to begin to show them. If your baby is premature, these milestones may occur somewhat later.  

While your baby's temperament tends to change little over time, his abilities and size will change rapidly. Remember that normal development patterns vary widely from one baby to the next. Do not feel anxious if your baby takes a developmental step later or earlier than someone else's infant. His developmental pattern is uniquely his own. If, however, you notice that your baby misses some of the developmental steps listed above or is consistently behind in the age when he begins to do them, bring it to the attention of the baby's doctor or nurse practitioner. Early detection and treatment may improve long-term development.   

Growth of Newborn

The main job for newborns is to grow. And in the first year, they do it in a big way. In that time most babies triple their birth weight and increase their length by about 50%.

From your newborn's first day, health care providers will keep track of your baby's weight, length, and head size. Why all this interest in your baby's size? Because growth is a good indicator of a newborn's general health. A child who is growing well is generally healthy, while poor growth can be a sign of a problem. 

How Much Do Newborns Weigh? 

Just like adults, newborns come in a range of healthy sizes. Most babies who are born full-term (between 37 and 40 weeks) weigh somewhere between 6lbs, 2oz (2,812 grams) and 9lbs, 2oz (4,173 grams). The average length for a full-term infant usually ranges from 19 to 21in (48 to 53 centimeters). 

If your full-term newborn is lighter or heavier than the average range, he is probably perfectly fine but might receive extra attention from the doctors and nurses after delivery just to make sure there are no problems. 

Various factors can affect a baby's size at birth. In many cases, the length of the pregnancy is a key factor. Babies born at their due date or later tend to be larger than those born earlier. Babies born prematurely, as discussed below, are often smaller than full-term babies.  Other factors include: 

Size of parents

• Tall parents may have larger-than-average newborns; short parents may have smaller-than-average newborns. 

Multiple births  

• If you are having twins, triplets, or more, you can count on your babies being relatively small. Multiples not only have to share their growing space in the uterus, they also are often born early, which leads to small size at birth. 

Birth order

• First babies are sometimes smaller than brothers or sisters born later. 

Gender   

• Girls tend to be smaller, boys larger, but the differences are slight at birth. 

Mother's health during pregnancy    

• Certain illnesses and habits can affect the weight of a newborn. Factors that can lead to a lower birth weight include a mother's high blood pressure, heart problems, or use of cigarettes, alcohol, or illegal drugs during the pregnancy. If the mother has diabetes, the baby may have a higher birth weight. All conditions that can affect a baby's weight should be closely monitored by the mother's doctor. In addition, women should not smoke, drink alcohol, or use illegal drugs during pregnancy.   

Nutrition during pregnancy

• Proper nutrition is essential for a baby's growth in the uterus and beyond. A poor diet during pregnancy can affect how much a newborn weighs and how the infant grows. 

Baby's health    

• Medical problems, including some birth defects and certain infections acquired during the pregnancy, can affect a child's birth weight and later growth.   

Growth and Premature Babies 

Premature babies generally are smaller and lighter than other newborns. A preemie's weight will be largely determined by how early he or she was born. The time the infant has missed being in the womb was growing time, so the baby has to do that growing in the outside world. 

Many pre-term babies are classified as having "low birth weight" or "very low birth weight." In medical terms, "low birth weight" means a baby weighs less than 5 pounds, 8 ounces (2,630 grams) at birth. That's the case for about 1 in every 13 babies in the US, so it's quite common. "Very low birth weight" means a baby weighs less than 3 pounds, 5 ounces (1,587 grams). Most babies with low or very low birth weight were born prematurely. 

Premature babies are given special medical attention immediately after birth, and a pediatric specialist called a neonatologist may be involved in their care. Many premature babies spend time in the neonatal intensive care unit (NICU) while they receive medical care, including feeding and observation of growth. 

Is Bigger Better? 

In the old days, a "strapping" baby with chubby cheeks and dimpled thighs was many people's picture of a healthy newborn. But a baby born much larger than average may have special medical problems that need attention. Some exceptionally large babies, especially those born to mothers with diabetes, including gestational diabetes, may have problems for a few days keeping blood sugar levels up and may require extra feedings, or even intravenous glucose, to prevent those levels from falling too low. 

How Much Do Newborns Grow? 

Babies are born with some extra fluid, so it is perfectly normal for a newborn to drop a few ounces when that fluid is lost in the first few days of life. A healthy newborn is expected to lose 7% to 10% of his or her birth weight but should regain that weight by about 2 weeks after birth. 

During their first month, most newborns continue to gain weight at a rate of at least 5 ounces (141 grams) a week. They generally grow in height about 1 to 1.5 inches (2.54 to 3.81 centimeters) during the first month. Many newborns go through a period of rapid growth when they are 7 to 10 days old and again at 3 and 6 weeks. 

Should I Be Concerned? 

Newborns are so small, and it can be hard to know if your baby is gaining weight the way he or she should. You may worry that your baby has lost too much weight in the first few days, or that he is not taking enough breast milk or formula. Most likely, everything is fine. But if you are concerned at all, check with your child's doctor. 

What's Next? 

Being small or large at birth does not necessarily mean a baby will be small or large later in childhood or as an adult. Plenty of towering teenagers began life as small babies, and the biggest baby on the block can grow up to be a petite adult. By and large, by the time they are adults, kids tend to resemble their parents in size. Genetics, as well as good nutrition and your attention, will play a large part in determining how your baby grows in the years to come. 

Whether your baby starts out large, small, or in between, in the next few months you can expect your infant to keep growing fast.